ABSTRACT
Enteral nutrition (EN) helps maintain gut barrier functions,including protecting mucosal structural integrity,promoting mucosal innate and acquired immunity,maintaining the balance and diversity of gut microbiota.Parenteral nutrition (PN) prevents progressive malnutrition and provides lifesaving therapy for many patients with gastrointestinal disorders.However,PN is associated with an increased incidence of infection in critically ill patients.Lack of EN during total parenteral nutrition (TPN) leads to disabled intestinal mucosal immunity with gut microbiota dysbiosis.Trophic feeding significantly restores intestinal mucosal immunity and promotes intestinal homeostasis.Dysbiosis aggregates inflammatory responses in intestinal mucosa during TPN,which could further impair intestinal mucosal immunity.Therefore,it's critical to clarify the interactions between nutritional support,gut microbiota and intestinal mucosal immunity.